P2 - Forces and Motion

• six vector quantities

  velocity,force,displacement,momentum,acceleration,weight
• four scalar quantities

  distance,speed,mass,energy
• the gradient on a distance time graph is the speed
• The area under a velocity-time graph represents distance travelled
• horizantal section on a distance graphs shows the object as stationary
• equation for acceleration=(v-u)/t
• gradient of a velocity time graph shoes the acceleration
• newtons first law states that Objects accelerate in the direction of the resultant force
• newtons second law is the acceleration of an object is directly proportional to the resultant force acting on it or F=m*a
• newtons third law states that for every action there is an equal and opposite reaction
• equation for momentum

  p=M*V
• newtons third law in relation to collisions

  total momentum before=total momentum after
• equation for stopping distance

  thinking+braking
• 5 things that affect breaking distance

  -the mass of the vehicle

  -the speed of the vehicle

  -the state of the vehicle's

  brakes

  -the state of the road

  -the amount of friction between the tyre and the road surface
• what can affect thinking distance

  the driver's reaction time which can be affected by drugs and distractions
• inertial mass is a meausre of how difficult it is to change the velocity of an object
• inertial mass = force/acceleration
• centripetal force is the resultant force for motion in a circle
• centripetal acts towards the centre of the circle
• an object moving in a circular orbit at constant speed is accelerating becuase it has a changing velocity